C

Scientist Detect Gravitational Waves

What is gravitational waves?(引力波)Scientists have for the first time observed ripples in the fabric of space-time(时空涟漪) called gravitational waves, arriving at the earth from a severely destructive event in the distant universe. It confirms a major prediction of Albert Einstein’s 1915 general theory of relativity and opens a unique new window onto the universe, according to a group of scientists at a press conference in Washington Thursday.
“This is truly scientific moonshot. We did it. We landed on the moon.”  declared David Reitz, executive director of the LIGO laboratory  at Caltech, at the conference in the National Press Club.
According to the National Science Foundation(NSF) experts, gravitational waves carry information about their dramatic origins and about the nature of gravity that cannot be obtained from elsewhere. Physicists have concluded that the detected gravitational waves were produced during the final fraction of a second(千分之一秒)of the combination of two black holes to produce a single, much bigger turning black hole. This fierce shock of two black holes had been predicted but never observed by NSF.
The gravitational waves were detected on Sept 14, 2015 at 5:51 am EDT by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington.
Based on the observed signals, LIGO scientists estimate that the black holes for this event were about 29 and 36 times the mass of the sun, and the event took place 1.3 billion years ago. About three times the mass of the sun was converted into gravitational waves in a fraction of a second -- with a peak power output about 50 times that of the whole visible universe. By looking at the time of arrival of the signals -- the detector in Livingston recorded the event 7 milliseconds before the detector in Hanford -- scientists can say that the source was located in the Southern Hemisphere, according to a press release from NSF, which funded the research.
The new LIGO discovery is the first observation of gravitational waves themselves, made by measuring the tiny disturbances the waves make to space and time as they pass through the earth. “Our observation of gravitational waves accomplishes an ambitious goal set out over five decades ago to directly detect this elusive phenomenon and better understand the universe, and, fittingly, fulfills Einstein’s legacy on the 100th anniversary of his general theory of relativity,” Reitze said.

74. By saying “This is truly scientific moonshot. We did it. We landed on the moon.”What does David Reitz mean?

A. We humans truly landed on the moon this time

B. The theory of relativity was not proved until now

C. Gravitational waves arrive at the earth in the end

D. Scientists successfully observed gravitational waves

75. What do NSF experts talk about in the third paragraph?

A. Gravitational waves carry information about the origins of nature

B. The nature of gravity cannot be obtained from gravitational waves

C. the combination of two black holes to produce a single, much bigger turning black hole.

D. Gravitational waves only appear the final fraction of a second of the combination of two black holes

76. According to the observed signals, LIGO scientists find out that ________________

A. the two black holes which brought about this event were much bigger than the sun

B. about three times the weight of the sun became gravitational waves in this event

C. the event produced by the observed signals took place 1.3billions years ago

D. the peak power output was about 50 times that of the whole universe

77. From the passage, a conclusion can be drawn that ______________

A. gravitational waves can make disturbances to space and time

B. Einstein predicted the observed gravitational waves in the universe

C. gravitational waves is not a puzzling phenomenon to the world any more

D. this new LIGO discovery was made to test the general theory of relativity

74-77 DCCB

第74题为推断题，我们定位第二段的这句话，该句子的意思是We have detected gravitational waves. We did it! 符合选项D，科学家成功的观察到了引力波。

第75题为段落大意题，问的是第三段中NFS专家在讨论什么，定位到第三段，the combination of two black holes to produce a single, much bigger turning black hole.说的是科学家一直在观测另外星系的两个黑洞动态。两个黑洞一直告诉旋转并相互靠拢，当两个黑洞碰撞时候，瞬间爆发出巨大能量，形成引力波向宇宙间扩散，符合选项。C

第76题为推断题，题目说的是，根据被观察到的信号来看，LIGO的科学家们发现了什么，定位到第五段the event took place 1.3 billion years ago，引力波波速以光速最终到达地球，大约花了13亿年时间，科学家在上周观察到了这段引力波，符合选项C。

第77题为全文推断题，故需要纵观全文并理解到位，才能得出答案，难度比较大。文中第二段It confirms a major prediction of Albert Einstein’s 1915 general theory of relativity and opens a unique new window onto the universe说的是爱因斯坦在100年前的广义相对论中预言了引力波存在，相对论广泛适用于地球和宇宙规律，宇宙间碰撞和能量转换会造成太空中形成涟漪般的波纹，符合选项B。